Apple recently launched a new Families webpage featuring tips on how to keep kids safe on their iOS device. It covers everything from the safe browsing to Apple's "Ask to Buy" tool. Ask to Buy allows the master device of a Family Sharing account to approve or decline any app downloads. Here's how to set up Ask to Buy on your iOS device:
Apple Family Sharing
Apple's new Family Sharing feature in iOS 8 allows users to share apps and other media purchased through the App Store and iTunes on up to six devices. To use Family Sharing you will need to establish one ‘master’ device that is connected to a credit card. The other five devices do not need to have access to the same Apple ID but will need permission from the master device to purchase any apps or media. You can find the new Family Sharing options under the iCloud settings of your device.
iOS 8 allows one credit card holder to add up to six total people to its Family Sharing feature. This allows anyone in the group to share purchases made from iTunes, iBooks and the App Store. Users can also access family photos, a family calendar, locations, and more. The new group sharing option also includes an "Ask Permission" feature so the card holder can approve or disprove all future iTunes, iBooks and App Store purchases.